Permanent blindness is the most severe disability seen with untreated IIH. As pressure in the brain increases, it will put pressure on your optic nerve, destroying its blood and nervous supply. Vision changes that occur rapidly, hours or days, should be assessed immediately. Your medical care may need to occur in the emergency room.
A worsening headache that is not typical to you is another reason to be seen by a medical provider immediately. In an emergency room setting, bloodwork, imaging, and procedure are performed in an expedited manner.
The emergency room team will likely not know what IIH is, but can identify pressing issues such as significant abnormalities in your results. A lumbar puncture can be performed in the emergency room which will provide information such as the opening pressure and rule out an infection.